Winter Contingency or Exodus for the number of Grunts on those levels.

Survivor - Earn 9 Sprees in a Firefight Matchmaking game - 2000cR

Sword, Sniper, Shotgun, Splatter & Wheelman are the easiest to get in Arcadefights at 5, 10 & 15 kills in their special ways, on top of that with the killing sprees ever 10 kills (after 50 the next one is 100)